The robot can be used and modified but the image has to say the following "Portions of this image are modifications based on work created and shared by Google and used according to terms described in the Creative Commons 3.0 Attribution License." They state in their terms and conditions they can remove any image that doesn't attribute the likeness to Google at any time. This is a requirement set out on Google's branding website. The official ANDROID logo is off limits ... also anything that says "android" by itself or "droid" as droid is owned by Lucas Films.